Two Nashville, Tenn., plastics recycling equipment suppliers are embroiled in a patent infringement lawsuit. Discovery in the case is scheduled to be completed by January. National Recovery Technologies Inc. filed the initial suit Feb. 9 against Magnetic Separation Systems Inc. in U.S. District Court in Nashville.
MSS followed with a countersuit filed Feb. 26.
NRT and MSS make equipment designed to detect different kinds of plastics in a waste stream. Both companies use X-ray detection to identify vinyl, which can destroy a load of PET.
``We developed the technology in 1989 and filed for a patent in 1990,'' said Guy Wentworth, NRT's vice president of corporate development. ``We got our first patent in 1993.''
That patent, involving electromagnetic radiation, was issued Nov. 9, 1993. The other patent in question, using electromagnetic sensing, was issued Aug. 23, 1994. NRT was formed in 1981.
NRT's equipment sorts bottles en masse. An important feature of the machine is that it can sort as many as 10 bottles a second - as many as fit on the width of a conveyor belt, Wentworth said.
NRT's MultiSort-brand uses a proprietary, high-speed, optical-scanning detection process that sorts bottles by resin type or color.
The firm's Vinylcycle-brand machine separates PVC from a mixed stream of whole or crushed plastic bottles of high density polyethylene, PET and PVC. It can separate 4,500 pounds per hour.
Wentworth said NRT discovered the patent infringement in January and filed the lawsuit shortly after.
``MSS brought out, recently, similar equipment using X-rays,'' he said.
However, MSS said NRT did not identify which MSS products were infringing on the patent, or which claims on the patents were infringed. MSS denied the allegations and filed a countersuit claiming that NRT's patents were invalid and that the company intentionally withheld prior products that would invalidate the patents.
MSS developed its BottleSort-brand system for automated sorting of commingled post-consumer plastic bottles in 1991. Its system for automatic detection of PVC bottles was developed in 1992 and the system for the removal of PVC flake from PET flake joined the lineup in 1994.
The MSS machines determine resin type and bottle colors using sensors. The Binary BottleSort-brand system, developed in 1995, uses two sensors. Computers identify each bottle, at a rate of 10 per second.
According to MSS, as many as five post-consumer plastic resins and seven colors of HDPE can be sorted on the BottleSort equipment.
Wentworth said NRT is suing for infringement and, if it wins, will ask to be compensated for damages.
No other companies will be sued, he added. MSS maintains that no infringement has taken place, and it will continue to design, manufacture and sell equipment, marketing manager Derek Vaughan said.